JP6600078B2 - Manufacturing method of optical film - Google Patents

Description

The present invention relates to an optical film manufacturing method and a mold. More specifically, the present invention relates to a method for producing an optical film having a nanometer-sized concavo-convex structure and a mold preferably used in the method for producing an optical film.

It is known that an optical film having a nanometer-sized uneven structure (nanostructure) has excellent antireflection properties. According to such a concavo-convex structure, since the refractive index continuously changes from the air layer to the base film, the reflected light can be dramatically reduced.

Nano Science Co., Ltd., “Knowledge of XPS analysis”, “Chemical state of carbon (C1s binding energy shift (chemical shift))”, [online], 2014, [searched on February 17, 2016], Internet (URL: http://www.nanoscience.co.jp/knowledge/XPS/knowledge02.html) A. M.M. Ferraria et al., "XPS studies on direct fluorinated HDPE: problems and solutions" (Polymers and solutions), Polymer 44, 2003, pp. 7241-7249 Thermo Fisher Scientific Inc., “Oxygen”, “Binding energies of common chemical states”, [online], 2013, [2016]. Search on the 17th of the month], Internet (URL: http://xpsimplified.com/elements/oxygen.php) N. Stobie et al., “Silver Doped Perfluoropolyether Urethane Coating: Antibacterial and Surface Analysis (Silver Doped Perfluoropolyethers: Antibacterial Activity and Surface Analysis. BioFols. 72, 2009, pp. 62-67

When manufacturing such an optical film, a mold for forming a concavo-convex structure is usually used. And in order to improve mold release property, the surface treatment by a mold release agent, ie, the mold release process, was sometimes performed with respect to the metal mold | die. However, as a result of studies by the present inventors, when a mold having insufficient release effect by a release agent is used, the resulting optical film has insufficient water repellency and oil repellency, that is, antifouling property. I understood that. For this reason, there is a problem that dirt such as fingerprints and oil attached to the surface of the optical film is likely to spread, and it is difficult to wipe off dirt that has entered between the convex portions. In addition, the frictional resistance of the surface of the optical film is increased (sliding property is lowered), and there is a problem that the abrasion resistance is lowered.

This invention is made | formed in view of the said present condition, and aims at providing the manufacturing method of the optical film excellent in antifouling property and abrasion resistance. Moreover, it aims at providing the metal mold | die used when manufacturing the optical film excellent in antifouling property and abrasion resistance.

The inventors of the present invention have studied various methods for producing an optical film having excellent antifouling properties and abrasion resistance. As a result, a lower layer resin and an upper layer resin are applied, and the two layers are laminated. We focused on the method of pressing the mold and forming a resin layer having a nanometer-sized uneven structure on the surface and then curing the resin layer. And it discovered that the density | concentration of the fluorine atom in the surface (surface of an uneven structure) of an optical film increased by including a fluorine-containing monomer in upper layer resin, and as a result, antifouling property and abrasion resistance increased. Further, a mold having a release agent containing fluorine atoms applied to the surface thereof is used, and the contact angle of hexadecane and the concentration of fluorine atoms on the surface of the mold applied with the release agent are set within a predetermined range. Thus, the inventors have found that the concentration of fluorine atoms on the surface of the optical film is remarkably increased, and as a result, the antifouling property and abrasion resistance are remarkably increased. As a result, the inventors have conceived that the above problems can be solved brilliantly and have reached the present invention.

That is, one embodiment of the present invention is a method for producing an optical film having a concavo-convex structure on the surface where a plurality of convex portions are provided at a pitch equal to or less than the wavelength of visible light, and a step of applying a lower layer resin and an upper layer resin (1 ) And the applied lower layer resin and the upper layer resin are laminated, a mold is pressed against the lower layer resin and the upper layer resin from the upper layer resin side to form a resin layer having the uneven structure on the surface. Including a step (2) and a step (3) for curing the resin layer, wherein the upper layer resin includes a fluorine-containing monomer, and a release agent is applied to a surface of the mold, and the release agent The mold includes carbon atoms, oxygen atoms, and fluorine atoms as constituent atoms, and the mold includes aluminum atoms and oxygen atoms as constituent atoms, and the mold to which the release agent is applied. Hexadeca on the surface Was added dropwise, theta / measured by 2 methods, the contact angle immediately after hexadecane dropwise theta _{A (Unit:} °), the contact angle after hexadecane dropwise 4 minutes theta _{B (unit:} °) and by defining, theta _A And θ _B is 85 ° or more, and the difference between θ _A and θ _B is 3.5 ° or less, the X-ray beam diameter is 100 μm, the analysis area is 1000 μm × 500 μm, and the photoelectron extraction angle is 45 °. The number of carbon atoms, the number of aluminum atoms, the number of oxygen atoms, and the number of fluorine atoms on the surface of the mold coated with the release agent, as measured by X-ray photoelectron spectroscopy under conditions The ratio of the number of fluorine atoms to the total number may be a method for producing an optical film that is 30 atom% or more.

Another aspect of the present invention is a mold in which a plurality of recesses are provided on the surface with a pitch equal to or smaller than the wavelength of visible light, and a mold release agent is disposed on the surface of the mold. The mold includes carbon atoms, oxygen atoms, and fluorine atoms as constituent atoms, the mold includes aluminum atoms and oxygen atoms as constituent atoms, and the mold in which the release agent is disposed. When hexadecane is dropped on the surface and measured by the θ / 2 method, the contact angle immediately after hexadecane drop is defined as θ _A (unit: °), and the contact angle after 4 minutes of hexadecane drop is defined as θ _B (unit: °). , Θ _A and θ _B are 85 ° or more, and the difference between θ _A and θ _B is 3.5 ° or less, the X-ray beam diameter is 100 μm, the analysis area is 1000 μm × 500 μm, and the photoelectron extraction angle By X-ray photoelectron spectroscopy at 45 ° The ratio of the number of fluorine atoms to the total number of carbon atoms, aluminum atoms, oxygen atoms, and fluorine atoms measured on the surface of the mold on which the release agent is disposed is The mold may be 30 atom% or more.

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the optical film excellent in antifouling property and abrasion resistance can be provided. Moreover, the metal mold | die used when manufacturing the optical film excellent in antifouling property and abrasion resistance can be provided.

It is a cross-sectional schematic diagram for demonstrating the manufacturing process of the optical film of Embodiment 1 (process ad). 1 is a schematic cross-sectional view showing a mold according to Embodiment 1. FIG. It is a cross-sectional schematic diagram for demonstrating the manufacturing process of the optical film of Embodiment 2. (process ae). It is a cross-sectional schematic diagram for demonstrating the manufacturing process of the optical film of Embodiment 3. (process ad). It is a cross-sectional schematic diagram for demonstrating the manufacturing process of the optical film of Embodiment 4. (process ae). It is a graph which shows the narrow spectrum of the surface of the optical film of Examples 1-3 and Comparative Examples 1 and 2, (a) shows a C1s peak, (b) shows a N1s peak, (c) shows O1s. A peak is shown, (d) shows an F1s peak. It is a graph which shows the analysis result of the C1s peak of Example 1 in Fig.6 (a). It is a graph which shows the analysis result of the C1s peak of Example 2 in Fig.6 (a). It is a graph which shows the analysis result of the C1s peak of Example 3 in Fig.6 (a). It is a graph which shows the analysis result of the C1s peak of the comparative example 1 in Fig.6 (a). It is a graph which shows the analysis result of the C1s peak of the comparative example 2 in Fig.6 (a). It is a graph which shows the analysis result of the O1s peak of Example 1 in FIG.6 (c). It is a graph which shows the analysis result of the O1s peak of Example 2 in FIG.6 (c). It is a graph which shows the analysis result of the O1s peak of Example 3 in FIG.6 (c). It is a graph which shows the analysis result of the O1s peak of the comparative example 1 in FIG.6 (c). It is a graph which shows the analysis result of the O1s peak of the comparative example 2 in FIG.6 (c).

Embodiments will be described below, and the present invention will be described in more detail with reference to the drawings. However, the present invention is not limited only to these embodiments. In addition, the configurations of the respective embodiments may be appropriately combined or changed within a range not departing from the gist of the present invention.

[Embodiment 1]
The manufacturing method of the optical film of Embodiment 1 is demonstrated below with reference to FIG. FIG. 1 is a schematic cross-sectional view for explaining a manufacturing process of the optical film of Embodiment 1 (steps a to d).

(A) Application of lower layer resin and upper layer resin First, the lower layer resin 5a is applied on the base film 2 as shown in FIG. On the other hand, the upper layer resin 5 b is applied on the mold 6. A mold release agent 7 is applied to the surface of the mold 6 in advance.

The coating method of the lower layer resin 5a and the upper layer resin 5b is not particularly limited, and examples thereof include a method of coating by a spray method, a gravure method, a slot die method, or the like. From the viewpoint of easily adjusting the film thickness and reducing the apparatus cost, a method of applying by a spray method is preferable. Among these, application using a swirl nozzle, electrostatic nozzle, or ultrasonic nozzle is particularly preferable.

(B) Formation of concavo-convex structure As shown in FIG. 1 (b), the mold 6 coated with the upper layer resin 5b is pressed against the lower layer resin 5a coated on the base film 2 from the upper layer resin 5b side. Thus, the upper resin 5b is laminated on the lower resin 5a, and at the same time, the concavo-convex structure is formed. As a result, a resin layer 8 having a concavo-convex structure on the surface opposite to the base film 2 is formed. In the resin layer 8, the lower layer resin 5a and the upper layer resin 5b are integrated, and there is no interface between them.

(C) The resin layer 8 on which the cured uneven structure of the resin layer is formed is cured (polymerized). As a result, a polymer layer 3 (cured product of the resin layer 8) as shown in FIG. 1C is formed.

The resin layer 8 is preferably cured by irradiation with active energy rays. In this specification, active energy rays refer to ultraviolet rays, visible rays, infrared rays, plasma, and the like. The resin layer 8 is preferably cured by ultraviolet rays. The active energy ray may be irradiated from the base film 2 side or from the resin layer 8 side. Moreover, the frequency | count of irradiation of the active energy ray with respect to the resin layer 8 is not specifically limited, One time may be sufficient and multiple times may be sufficient.

(D) Mold Release The mold 6 having the release agent 7 applied on its surface is released from the polymer layer 3. As a result, the optical film 1 as shown in FIG. The concavo-convex structure formed on the surface of the polymer layer 3 opposite to the base film 2 has a plurality of convex portions (projections) 4 having a pitch less than the wavelength of visible light (distance between vertices of adjacent convex portions 4). ) Corresponds to a structure provided by P, that is, a moth-eye structure (an eye-like structure). Therefore, the optical film 1 corresponds to an antireflection film having a moth-eye structure on the surface. Thereby, the optical film 1 can show the excellent antireflection property (low reflectivity) by a moth-eye structure.

In the manufacturing process described above, for example, if the base film 2 is formed into a roll shape, the steps (a) to (d) can be performed continuously and efficiently.

Then, each member used when manufacturing the optical film 1 is demonstrated below.

Examples of the material for the base film 2 include triacetyl cellulose (TAC), polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), cycloolefin polymer (COP), and polycarbonate (PC). You may choose according to it. According to such a material, the base film 2 having high hardness and excellent transparency and weather resistance can be obtained. The base film 2 may be subjected to an easy adhesion treatment. For example, a triacetyl cellulose film (TAC film) subjected to the easy adhesion treatment or the like is used. Further, the base film 2 may be subjected to saponification treatment. For example, a triacetyl cellulose film (TAC film) subjected to saponification treatment or the like is used.

Although the thickness of the base film 2 is not particularly limited, it is preferably 10 μm or more and 120 μm or less, and more preferably 40 μm or more and 80 μm or less from the viewpoint of ensuring transparency and workability.

The upper layer resin 5b contains a fluorine-containing monomer. When the upper layer resin 5b contains the fluorine-containing monomer, the concentration of fluorine atoms on the surface of the polymer layer 3 opposite to the base film 2 is increased. As a result, the surface energy of the polymer layer 3 is lowered, and the optical film 1 having excellent antifouling properties can be obtained. Moreover, the slipperiness of the surface on the opposite side to the base film 2 of the polymer layer 3 increases, and the optical film 1 excellent in abrasion resistance is obtained.

The fluorine-containing monomer has a reactive site and a site containing at least one selected from the group consisting of a fluoroalkyl group, a fluorooxyalkyl group, a fluoroalkenyl group, a fluoroalkanediyl group, and a fluorooxyalkanediyl group. It is preferable to have.

The reactive site refers to a site that reacts with other components by external energy such as light and heat. Examples of such reactive sites include alkoxysilyl groups, silyl ether groups, hydrolyzed silanol groups, carboxyl groups, hydroxyl groups, epoxy groups, vinyl groups, allyl groups, acryloyl groups, methacryloyl groups, and the like. It is done. The reactive site is preferably an alkoxysilyl group, a silyl ether group, a silanol group, an epoxy group, a vinyl group, an allyl group, an acryloyl group, or a methacryloyl group from the viewpoint of reactivity and handling properties, and a vinyl group or an allyl group. An acryloyl group or a methacryloyl group is more preferable, and an acryloyl group or a methacryloyl group is particularly preferable.

A fluoroalkyl group, a fluorooxyalkyl group, a fluoroalkenyl group, a fluoroalkanediyl group, and a fluorooxyalkanediyl group are respectively an alkyl group, an oxyalkyl group, an alkenyl group, an alkanediyl group, and an oxyalkanediyl group. It is a substituent in which at least part of the hydrogen atoms it has are substituted with fluorine atoms. A fluoroalkyl group, a fluorooxyalkyl group, a fluoroalkenyl group, a fluoroalkanediyl group, and a fluorooxyalkanediyl group are all substituents mainly composed of fluorine atoms and carbon atoms, and are branched in the structure. May be present, and a plurality of these substituents may be linked.

An example of the fluorine-containing monomer is represented by the following general formula (A).
R ^f1 -R ² -D ¹ (A)
In the general formula (A), R ^f1 is a moiety containing at least one selected from the group consisting of a fluoroalkyl group, a fluorooxyalkyl group, a fluoroalkenyl group, a fluoroalkanediyl group, and a fluorooxyalkanediyl group. Represents. R ² represents an alkanediyl group, an alkanetriyl group, or an ester structure, urethane structure, ether structure, or triazine structure derived therefrom. D ¹ represents a reactive site.

Examples of the fluorine-containing monomer represented by the general formula (A) include 2,2,2-trifluoroethyl acrylate, 2,2,3,3,3-pentafluoropropyl acrylate, and 2-perfluorobutyl. Ethyl acrylate, 3-perfluorobutyl-2-hydroxypropyl acrylate, 2-perfluorohexyl ethyl acrylate, 3-perfluorohexyl-2-hydroxypropyl acrylate, 2-perfluorooctyl ethyl acrylate, 3-perfluorooctyl-2 -Hydroxypropyl acrylate, 2-perfluorodecylethyl acrylate, 2-perfluoro-3-methylbutylethyl acrylate, 3-perfluoro-3-methoxybutyl-2-hydroxypropyl acrylate, 2-perfluoro-5 Methylhexylethyl acrylate, 3-perfluoro-5-methylhexyl-2-hydroxypropyl acrylate, 2-perfluoro-7-methyloctyl-2-hydroxypropyl acrylate, tetrafluoropropyl acrylate, octafluoropentyl acrylate, dodecafluoroheptyl Acrylate, hexadecafluorononyl acrylate, hexafluorobutyl acrylate, 2,2,2-trifluoroethyl methacrylate, 2,2,3,3,3-pentafluoropropyl methacrylate, 2-perfluorobutylethyl methacrylate, 3-par Fluorobutyl-2-hydroxypropyl methacrylate, 2-perfluorooctylethyl methacrylate, 3-perfluorooctyl-2-hydroxypropylene Methacrylate, 2-perfluorodecylethyl methacrylate, 2-perfluoro-3-methylbutylethyl methacrylate, 3-perfluoro-3-methylbutyl-2-hydroxypropyl methacrylate, 2-perfluoro-5-methylhexylethyl methacrylate, 3 -Perfluoro-5-methylhexyl-2-hydroxypropyl methacrylate, 2-perfluoro-7-methyloctylethyl methacrylate, 3-perfluoro-7-methyloctylethyl methacrylate, tetrafluoropropyl methacrylate, octafluoropentyl methacrylate, dodeca Fluoroheptyl methacrylate, hexadecafluorononyl methacrylate, 1-trifluoromethyl trifluoroethyl methacrylate, hexafluorobut Examples include til methacrylate, triacryloyl-heptadecafluorononenyl-pentaerythritol, and the like.

As a preferable material of the fluorine-containing monomer, for example, a material having a fluoropolyether moiety can be mentioned. The fluoropolyether moiety is a moiety composed of a fluoroalkyl group, an oxyfluoroalkyl group, an oxyfluoroalkyldiyl group, etc., and has a structure represented by the following general formula (B) or (C).
_{CF n1 H (3-n1)} - (CF n2 H (2-n2)) k O- (CF n3 H (2-n3)) m O- (B)
_{- (CF n4 H (2-} n4)) p O- (CF n5 H (2-n5)) s O- (C)
In the general formulas (B) and (C), n1 is an integer of 1 to 3, n2 to n5 are 1 or 2, and k, m, p, and s are integers of 0 or more. A preferable combination of n1 to n5 is a combination in which n1 is 2 or 3, and n2 to n5 is 1 or 2, and a more preferable combination is n1 is 3, n2 and n4 are 2, n3 and n5 are 1 or 2 is a combination.

The number of carbon atoms contained in the fluoropolyether moiety is preferably 4 or more and 12 or less, more preferably 4 or more and 10 or less, and still more preferably 6 or more and 8 or less. When the number of carbon atoms is less than 4, there is a concern that the surface energy is reduced. When the number of carbon atoms is more than 12, there is a concern that the solubility in a solvent is lowered. In addition, the fluorine-containing monomer may have a plurality of fluoropolyether sites per molecule.

Known fluorine-containing compounds containing a fluorine-containing monomer as a constituent component include, for example, a fluorine-based additive (product name: OPTOOL (registered trademark) DAC-HP) manufactured by Daikin Industries, Ltd. and fluorine manufactured by Daikin Industries, Ltd. Additive (Product name: Optool DSX), Fluorine additive manufactured by Daikin Industries, Ltd. (Product name: Optool AES4), Fluorine additive manufactured by Asahi Glass (Product name: Afluid), Fluorine additive manufactured by DIC Agent (product name: MegaFac (registered trademark) RS-76-NS), fluorine-based additive manufactured by DIC (product name: Megafac RS-75), fluorine-based additive manufactured by Yushi Co., Ltd. (product name: C10GACRY), a fluorine-based additive (product name: C8HGOL) manufactured by Yushi Co., Ltd., and the like. The fluorine-containing monomer is preferably one that is polymerized by ultraviolet rays, and preferably has a —OCF ₂ — chain and / or a = NCO— chain. The upper resin 5b may contain one type of fluorine-containing monomer or may contain a plurality of types of fluorine-containing monomers.

The fluorine-containing monomer may also be contained in the lower layer resin 5a. In this case, the concentration of the fluorine-containing monomer in the upper resin 5b is preferably higher than the concentration of the fluorine-containing monomer in the lower resin 5a. The lower layer resin 5a preferably does not contain a fluorine-containing monomer.

The concentration of the fluorine-containing monomer in the upper layer resin 5b is preferably higher than 0% by weight and 10% by weight or less. When the concentration of the fluorine-containing monomer in the upper layer resin 5b is higher than 10% by weight, there is a concern about the occurrence of bleed-out and an increase in cost due to too much fluorine-containing monomer.

Each of the lower layer resin 5a and the upper layer resin 5b may appropriately include a polyfunctional acrylate, a monofunctional acrylate, a polymerization initiator, and the like.

Examples of polyfunctional acrylates include urethane acrylate, ethoxylated pentaerythritol tetraacrylate, pentaerythritol triacrylate, 1,9-nonanediol diacrylate, dipentaerythritol hexaacrylate, tripentaerythritol acrylate, and mono and dipentaerythritol acrylate. And polypentaerythritol acrylate, ethoxylated polyglycerin polyacrylate, trimethylolpropane triacrylate, alkoxylated dipentaerythritol polyacrylate, polyethylene glycol 200 diacrylate, polyethylene glycol 300 diacrylate, polyethylene glycol 400 diacrylate, polyethylene Glycol 600 Diac Relay , Hexafunctional polyester acrylate, ethoxylated glycerin triacrylate, 1,6-hexanediol diacrylate, tripropylene glycol diacrylate, ethoxylated (4 mol adduct) Bisphenol A diacrylate, dipropylene glycol diacrylate, and the like. Known urethane acrylates include, for example, Kyoeisha Chemical Co., Ltd. polyfunctional acrylate (product name: UA-306H), Shin-Nakamura Chemical Co., Ltd. polyfunctional acrylate (product name: U-10PA), Shin-Nakamura. Examples thereof include polyfunctional acrylate (product name: UA-7100) manufactured by Chemical Industries. Examples of known ethoxylated pentaerythritol tetraacrylate include polyfunctional acrylate (product name: ATM-35E) manufactured by Shin-Nakamura Chemical Co., Ltd. Known examples of pentaerythritol triacrylate include, for example, polyfunctional acrylate (product name: A-TMM-3LM-N) manufactured by Shin-Nakamura Chemical Co., Ltd., polyfunctional acrylate (product name) manufactured by Shin-Nakamura Chemical Co., Ltd. : A-TMM-3L), a polyfunctional acrylate (product name: PET-3) manufactured by Daiichi Kogyo Seiyaku Co., Ltd., and the like. Known examples of 1,9-nonanediol diacrylate include polyfunctional acrylate (product name: A-NOD-N) manufactured by Shin-Nakamura Chemical Co., Ltd. Known examples of dipentaerythritol hexaacrylate include, for example, polyfunctional acrylate (product name: Light acrylate DPE-6A) manufactured by Kyoeisha Chemical Co., Ltd., and polyfunctional acrylate (product name: A-) manufactured by Shin-Nakamura Chemical Co., Ltd. DPH) and the like. Examples of the mixture of tripentaerythritol acrylate, mono- and dipentaerythritol acrylate, and polypentaerythritol acrylate include polyfunctional acrylate (product name: Biscote # 802) manufactured by Osaka Organic Chemical Industry Co., Ltd. Examples of the ethoxylated polyglycerin polyacrylate include polyfunctional acrylate (product name: NK ECONOMER (registered trademark) A-PG5027E) manufactured by Shin-Nakamura Chemical Co., Ltd. Examples of known trimethylolpropane triacrylate include polyfunctional acrylate (product name: light acrylate TMP-A) manufactured by Kyoeisha Chemical Co., Ltd. Known examples of the alkoxylated dipentaerythritol polyacrylate include, for example, a polyfunctional acrylate manufactured by Nippon Kayaku Co., Ltd. (product name: KAYARAD (registered trademark) DPEA-12), a polyfunctional acrylate manufactured by Nippon Kayaku Co., Ltd. ( Product name: KAYARAD DPCA-30) and the like. Examples of known polyethylene glycol 200 diacrylate include polyfunctional acrylate (product name: PE-200) manufactured by Daiichi Kogyo Seiyaku Co., Ltd. Examples of known polyethylene glycol 300 diacrylate include polyfunctional acrylate (product name: PE-300) manufactured by Daiichi Kogyo Seiyaku Co., Ltd. Examples of known polyethylene glycol 400 diacrylate include polyfunctional acrylate (product name: A-400) manufactured by Shin-Nakamura Chemical Co., Ltd. Examples of known polyethylene glycol 600 diacrylate include polyfunctional acrylate (product name: A-600) manufactured by Shin-Nakamura Chemical Co., Ltd. As a well-known thing among hexafunctional polyester acrylates, the polyfunctional acrylate (product name: EBECRYL (trademark) 450) by Daicel Ornex, etc. are mentioned, for example. Examples of known ethoxylated glycerin triacrylate include polyfunctional acrylate (product name: A-GLY-9E) manufactured by Shin-Nakamura Chemical Co., Ltd. Known examples of 1,6-hexanediol diacrylate include, for example, polyfunctional acrylate (product name: A-HD-N) manufactured by Shin-Nakamura Chemical Co., Ltd. Examples of known tripropylene glycol diacrylate include polyfunctional acrylate (product name: APG-200) manufactured by Shin-Nakamura Chemical Co., Ltd. Known examples of ethoxylated (4 mol adduct) bisphenol A diacrylate include, for example, polyfunctional acrylate (product name: A-BPE-4) manufactured by Shin-Nakamura Chemical Co., Ltd. As a well-known thing among dipropylene glycol diacrylate, the Shin-Nakamura Chemical Co., Ltd. polyfunctional acrylate (product name: APG-100) etc. are mentioned, for example. Each of the lower layer resin 5a and the upper layer resin 5b may include one type of polyfunctional acrylate, or may include a plurality of types of polyfunctional acrylates.

Examples of monofunctional acrylates containing an alkyl group include lauryl acrylate and stearyl acrylate. Examples of known lauryl acrylate include monofunctional acrylate (product name: LA) manufactured by Shin-Nakamura Chemical Co., Ltd. Known examples of stearyl acrylate include a monofunctional acrylate (product name: Blemmer (registered trademark) SA) manufactured by NOF Corporation.

Among monofunctional acrylates, those containing an ethylene oxide group or a propylene oxide group include, for example, polyethylene glycol monoacrylate and polypropylene glycol monoacrylate. Examples of known polyethylene glycol monoacrylates include monofunctional acrylates (product name: AM-90G) manufactured by Shin-Nakamura Chemical Co., Ltd. As a well-known thing among polypropylene glycol monoacrylates, the monofunctional acrylate (product name: BLEMMER AP-400) by NOF Corporation etc. are mentioned, for example.

Among monofunctional acrylates, those containing a hydroxyl group include, for example, 2-hydroxyethyl methacrylate, 4-hydroxybutyl acrylate, and the like. Examples of known 2-hydroxyethyl methacrylate include monofunctional acrylate (product name: 2HEMA) manufactured by Nippon Shokubai Co., Ltd. Known examples of 4-hydroxybutyl acrylate include, for example, a monofunctional acrylate (product name: 4HBA) manufactured by Nippon Kasei Co., Ltd.

Examples of monofunctional acrylates containing amide groups (hereinafter also referred to as monofunctional amide monomers) include, for example, N-acryloylmorpholine, N, N-dimethylacrylamide, N, N-diethylacrylamide, and N-vinyl. -2-pyrrolidone, N, N-dimethylmethacrylamide, N-methoxy-N-methyl-3-phenyl-acrylamide and the like. Known examples of N-acryloylmorpholine include monofunctional amide monomers (product name: ACMO (registered trademark)) manufactured by KJ Chemicals. Known examples of N, N-dimethylacrylamide include monofunctional amide monomers (product name: DMAA (registered trademark)) manufactured by KJ Chemicals. Known examples of N, N-diethylacrylamide include monofunctional amide monomers (product name: DEAA (registered trademark)) manufactured by KJ Chemicals. Known examples of N-vinyl-2-pyrrolidone include a monofunctional amide monomer (product name: N-vinylpyrrolidone) manufactured by Nippon Shokubai Co., Ltd. Known examples of N, N-dimethylmethacrylamide include monofunctional amide monomers (product code: D0745) manufactured by Tokyo Chemical Industry Co., Ltd. Examples of known N-methoxy-N-methyl-3-phenyl-acrylamide include monofunctional amide monomers manufactured by Sigma-Aldrich.

When the lower layer resin 5a contains a monofunctional amide monomer, the adhesion between the base film 2 and the polymer layer 3 can be enhanced by the hydrogen bonding force of the amide group. In particular, when the base film 2 contains highly polar triacetyl cellulose, more specifically, even when triacetyl cellulose is present on at least the surface of the base film 2 on the polymer layer 3 side, The adhesion between the material film 2 and the polymer layer 3 can be enhanced. The monofunctional amide monomer preferably contains at least one of N, N-dimethylacrylamide and N, N-diethylacrylamide. Since N, N-dimethylacrylamide and N, N-diethylacrylamide have a large molecular weight among monofunctional amide monomers and a low glass transition temperature, even if the content is small, the base film 2 and the polymer Adhesiveness with the layer 3 can be preferably increased.

Each of the lower layer resin 5a and the upper layer resin 5b may include one type of monofunctional acrylate, or may include a plurality of types of monofunctional acrylates.

Examples of the polymerization initiator include a photopolymerization initiator. The photopolymerization initiator is active with respect to active energy rays, and is added to initiate a polymerization reaction for polymerizing the monomer. As the photopolymerization initiator, for example, a radical polymerization initiator, an anionic polymerization initiator, a cationic polymerization initiator and the like can be used. Examples of such a photopolymerization initiator include acetophenones such as p-tert-butyltrichloroacetophenone, 2,2′-diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one; Ketones such as benzophenone, 4,4′-bisdimethylaminobenzophenone, 2-chlorothioxanthone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone; benzoin, benzoin methyl ether, benzoin isopropyl ether, benzoin isobutyl ether, etc. Benzoin ethers; benzyl ketals such as benzyl dimethyl ketal and hydroxycyclohexyl phenyl ketone; 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide; Scan (2,4,6-trimethylbenzoyl) - acylphosphine oxides such as triphenylphosphine oxide; 1-hydroxy - cyclohexyl - phenyl - phenones such as ketones, and the like. Known examples of 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide include, for example, a photopolymerization initiator (product name: IRGACURE (registered trademark) TPO) manufactured by BASF. Examples of known bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide include a photopolymerization initiator (product name: IRGACURE 819) manufactured by BASF. Known examples of 1-hydroxy-cyclohexyl-phenyl-ketone include a photopolymerization initiator (product name: IRGACURE 184) manufactured by BASF.

It is preferable that at least one of the lower layer resin 5a and the upper layer resin 5b does not contain a solvent. That is, at least one of the lower layer resin 5a and the upper layer resin 5b is preferably solventless. When at least one of the lower layer resin 5a and the upper layer resin 5b is a solventless system, it is possible to reduce the cost associated with the use of the solvent and the environmental load (odor during use, etc.). Furthermore, an apparatus for drying and removing the solvent is unnecessary, and the apparatus cost can be reduced. On the other hand, when the upper layer resin 5b contains a solvent, the fluorine-containing monomer is excessively mixed, and there is a concern that the fluorine atoms are less likely to be oriented on the surface of the polymer layer 3 opposite to the base film 2.

The thickness Da of the lower layer resin 5a is not particularly limited, but is preferably 5 μm or more and 10 μm or less. When the thickness Da of the lower layer resin 5a is less than 5 μm, the applicability of the lower layer resin 5a may be deteriorated (defects such as spots and lens defects occur). When the thickness Da of the lower layer resin 5a is larger than 10 μm, the obtained optical film 1 may be easily curled. The thickness Da of the lower layer resin 5a in the present embodiment indicates the distance from the surface on the base film 2 side to the surface on the opposite side to the base film 2 as shown in FIG.

The viscosity of the lower layer resin 5a is preferably higher than 10 cp and lower than 10,000 cp at 25 ° C. When the viscosity at 25 ° C. of the lower layer resin 5a is higher than 10 cp, the fluorine-containing monomer in the upper layer resin 5b is less likely to be mixed into the lower layer resin 5a in a state where the lower layer resin 5a and the upper layer resin 5b are laminated. The concentration of fluorine atoms on the surface of the resin 5b (polymer layer 3) opposite to the base film 2 tends to increase. When the viscosity of the lower layer resin 5a at 25 ° C. is less than 10,000 cp, the coating property of the lower layer resin 5a is improved, and the thickness of the lower layer resin 5a can be easily controlled.

The thickness Db of the upper layer resin 5b is not particularly limited, but is preferably 0.5 μm or more and 2 μm or less. As shown in FIG. 1A, the thickness Db of the upper layer resin 5b in the present embodiment is on the side opposite to the mold 6 (release agent 7) from the position corresponding to the bottom point of the recess of the mold 6. Refers to the distance to the surface.

The viscosity of the upper layer resin 5b is preferably higher than 0.1 cp and lower than 100 cp at 25 ° C. When the viscosity of the upper resin 5b at 25 ° C. is higher than 0.1 cp, the applicability of the upper resin 5b is enhanced, and the thickness of the upper resin 5b can be easily controlled. When the viscosity of the upper resin 5b at 25 ° C. is less than 100 cp, the fluidity of the fluorine-containing monomer in the upper resin 5b is preferably ensured. Therefore, in a state where the lower layer resin 5a and the upper layer resin 5b are laminated, the fluorine-containing monomer in the upper layer resin 5b is not easily mixed into the lower layer resin 5a, and the base film 2 of the upper layer resin 5b (polymer layer 3). It becomes easy to increase the concentration of fluorine atoms on the opposite surface.

The mold 6 has a plurality of recesses provided on the surface at a pitch Q (distance between the bottom points of adjacent recesses) Q that is equal to or less than the wavelength of visible light. Therefore, according to the mold 6, a moth-eye structure can be formed on the surface of the resin layer 8.

The mold 6 contains aluminum atoms and oxygen atoms as constituent atoms. As the mold 6, for example, one produced by the following method can be used. First, aluminum as a material for the mold 6 is formed on the support substrate by sputtering. Next, a female mold (mold 6) having a moth-eye structure can be produced by alternately repeating anodic oxidation and etching on the formed aluminum layer. At this time, the concavo-convex structure of the mold 6 can be changed by adjusting the time for performing anodic oxidation and the time for performing etching.

The material of the support substrate is not particularly limited. For example, glass; metal material such as stainless steel and nickel; polypropylene, polymethylpentene, cyclic olefin polymer (typically, norbornene resin, etc., Nippon Zeon Co., Ltd.) Polyolefin resins such as polymers (product name: ZEONOR (registered trademark)) and polymers manufactured by JSR (product name: ARTON (registered trademark)); polycarbonate resins; polyethylene terephthalate, polyethylene naphthalate, triacetyl Examples thereof include resin materials such as cellulose. An aluminum substrate may be used instead of the aluminum film formed on the support substrate.

The shape of the mold 6 is not particularly limited, and examples thereof include a flat plate shape and a roll shape.

The pitch Q between adjacent concave portions is not particularly limited as long as it is equal to or less than the wavelength of visible light (780 nm), but from the viewpoint of realizing a preferable pitch P between adjacent convex portions 4 of the optical film 1 described later, 100 nm or more, It is preferably 400 nm or less, and more preferably 100 nm or more and 200 nm or less. In this specification, the pitch between the adjacent concave portions of the mold is all in a 1 μm square region of a planar photograph taken with a scanning electron microscope (product name: S-4700) manufactured by Hitachi High-Technologies Corporation. The average value of the distance between adjacent recessed parts is indicated.

A mold release agent 7 is applied to the surface of the mold 6. Therefore, the mold 6 can be easily peeled from the polymer layer 3 in the step (d). Furthermore, the surface energy of the mold 6 can be lowered. Therefore, in the step (b), when the mold 6 is pressed from the upper resin 5b side to the lower resin 5a, fluorine atoms are efficiently oriented on the surface of the upper resin 5b opposite to the base film 2. Can do. Furthermore, before hardening the resin layer 8, it can prevent that a fluorine atom leaves | separates from the surface on the opposite side to the base film 2 of the resin layer 8. FIG. As a result, in the optical film 1, fluorine atoms can be efficiently oriented on the surface of the polymer layer 3 opposite to the base film 2.

The release agent 7 contains carbon atoms, oxygen atoms, and fluorine atoms as constituent atoms. Since the release agent 7 contains a fluorine atom, the interaction with the fluorine-containing monomer in the upper layer resin 5b is strengthened, and the fluorine atom in the upper layer resin 5b is more efficient on the surface opposite to the base film 2. Can be oriented.

Examples of the release agent 7 include those containing a fluorine-containing compound. Known fluorine-containing compounds include, for example, a fluorine-based additive (product name: OPTOOL (registered trademark) DAC-HP) manufactured by Daikin Industries, Ltd., and a fluorine-based additive (product name: OPTOOL manufactured by Daikin Industries, Ltd.). DSX), a fluorine-based additive (product name: OPTOOL AES4) manufactured by Daikin Industries, Ltd., a fluorine-based additive manufactured by Asahi Glass (product name: Afluid), a fluorine-based additive manufactured by DIC (product name: Megafuck ( (Registered trademark) RS-76-NS), a fluorine-based additive (product name: MegaFac RS-75) manufactured by DIC, a fluorine-based additive (product name: C10GACRY) manufactured by Yushi Co., Ltd. Fluorine-based additives (product name: C8HGOL) and the like.

For example, “OPTOOL DAC-HP” manufactured by Daikin Industries, Ltd. is a blend of the following materials. In addition, the numerical value attached | subjected to each material shows the mixture ratio of each material.
Fluorine-containing compound: 15% by weight or more and 25% by weight or less 1,1,2,2,3,3,4-heptafluorocyclopentane: 45% by weight or more and 55% by weight or lessPropylene glycol monomethyl ether: 25 % By weight to 35% by weight

For example, “OPTOOL DSX” manufactured by Daikin Industries, Ltd. is a blend of the following materials. In addition, the numerical value attached | subjected to each material shows the mixture ratio of each material.
-Fluorine-containing compound: 15 wt% or more, 25 wt% or less-Perfluorohexane: 75 wt% or more, 85 wt% or less

Hexadecane is dropped on the surface of the mold 6 to which the release agent 7 is applied, and the contact angle immediately after the hexadecane drop measured by the θ / 2 method is θ _A (unit: °), contact after 4 minutes of hexadecane drop. If the angle is defined as θ _B (unit: °), θ _A and θ _B are 85 ° or more, and the difference between θ _A and θ _B is 3.5 ° or less. θ _A and θ _B are preferably 90 ° or more, and the difference between θ _A and θ _B is preferably 3 ° or less. θ _A and θ _B are preferably as large as possible, but a preferable upper limit value of θ _A and θ _B is 150 °. In this specification, the surface of the mold to which the release agent is applied (arranged) is substantially the surface of the release agent applied (arranged) on the mold (the surface opposite to the mold). including. In the present specification, immediately after the hexadecane is added, it refers to within 0.5 seconds after the dropped hexadecane contacts the surface of the mold on which the release agent is applied (arranged). In this specification, the contact angle is the θ / 2 method (θ / 2 = arctan (h / r), θ: contact) using a portable contact angle meter (product name: PCA-1) manufactured by Kyowa Interface Science Co., Ltd. Angle, r: droplet radius, h: droplet height) and the average value of three contact angles. Here, as the first measurement point, the center portion of the sample is selected, and as the second and third measurement points, 25 mm away from the first measurement point in the longitudinal direction of the sample, and Two points that are point-symmetric with respect to the first measurement point are selected.

A release agent 7 is applied which is measured by X-ray photoelectron spectroscopy (XPS) under conditions of an X-ray beam diameter of 100 μm, an analysis area of 1000 μm × 500 μm, and a photoelectron extraction angle of 45 °. The ratio of the number of fluorine atoms to the total number of carbon atoms, the number of aluminum atoms, the number of oxygen atoms, and the number of fluorine atoms (hereinafter also referred to as fluorine content) on the surface of the mold 6 formed. , 30 atom% or more. The fluorine content on the surface of the mold 6 to which the release agent 7 is applied is preferably 43 atom% or more, and more preferably 49 atom% or more. A preferable upper limit of the fluorine content on the surface of the mold 6 to which the release agent 7 is applied is 55 atom%, and a more preferable upper limit is 50 atom%. When the fluorine content on the surface of the mold 6 to which the release agent 7 is applied is higher than 55 atom%, the resulting polymer layer 3 may become cloudy. In the present specification, the fluorine content was measured using an X-ray photoelectron spectroscopic analyzer (product name: PHI Quantera SXM) manufactured by ULVAC-PHI, and the apparatus specifications were as follows.
X-ray source: Monochromatic AlKα ray (1486.6 eV)
・ Spectroscope: Electrostatic concentric hemisphere analyzer ・ Amplifier: Multi-channel type

In addition to including the fluorine-containing monomer in the upper layer resin 5b, if the contact angle of hexadecane and the fluorine content on the surface of the mold 6 coated with the release agent 7 are within the above ranges, the polymer layer 3 The density | concentration of the fluorine atom in the surface on the opposite side to the base film 2 increases notably. As a result, antifouling property and abrasion resistance can be remarkably enhanced. On the other hand, when the mold release effect by the mold release agent 7 is insufficient, at least one of the contact angle of hexadecane and the fluorine content on the surface of the mold 6 coated with the mold release agent 7 is It will be outside the above range. For example, when the step (b) is continuously performed for a long period of time, the release effect by the release agent 7 is gradually reduced. Therefore, if the step (b) is continued as it is, there is a concern that the material (aluminum) of the mold 6 will be peeled off and the uneven structure cannot be formed. In addition, when using the metal mold | die 6 by which the mold release agent 7 was not apply | coated to the surface, the material (aluminum) of the metal mold | die 6 might peel similarly. As described above, from the viewpoint of maintaining the release effect by the release agent 7, the release agent 7 can be supplied to the surface of the mold 6 in the manufacturing process of the optical film 1 (for example, the release agent every predetermined time) 7) is preferably provided.

The thickness Dc of the release agent 7 is not particularly limited, but is preferably 1 nm or more and 5 nm or less. When the thickness Dc of the mold release agent 7 is less than 1 nm, the mold release agent 7 and the surface (hydroxyl group) of the mold 6 are efficiently bonded and do not adhere to each other. Further, the fluorine-containing monomer in the mold release agent 7 There is a concern that the chain formed by cross-linking of the (fluorine-based monomolecular monomers) does not become long (the cross-linking strength does not increase), and as a result, the release effect by the release agent 7 is reduced. When the thickness Dc of the release agent 7 is larger than 5 nm, the surface shape of the release agent 7 does not reflect the uneven structure of the mold 6, and as a result, the moth-eye structure formed by the mold 6 changes. However, there is a concern that the antireflection property and the mechanical performance are lowered. The thickness Dc of the release agent 7 in the present embodiment indicates the distance from the surface on the mold 6 side to the surface on the opposite side to the mold 6 as shown in FIG.

The thickness D of the polymer layer 3 is not particularly limited, but it is preferably thin from the viewpoint of orienting fluorine atoms on the surface of the polymer layer 3 opposite to the base film 2 at a high concentration. Specifically, it is preferably 5 μm or more and 10 μm or less. When the thickness D of the polymer layer 3 is less than 5 μm, there is a concern that defects such as spots and lens defects may occur when the polymer layer 3 is formed. When the thickness D of the polymer layer 3 is larger than 10 μm, the obtained optical film 1 may be easily curled. The thickness D of the polymer layer 3 in the present embodiment indicates the distance from the surface on the base film 2 side to the apex of the convex portion 4 as shown in FIG.

The shape of the convex portion 4 is not particularly limited, and for example, it is narrower toward the tip, such as a shape (bell shape) constituted by a columnar lower portion and a hemispherical upper portion, a cone shape (cone shape, conical shape), or the like. The shape (taper shape) which becomes. Further, the convex portion 4 may have a shape having a branch protrusion. The branch protrusion indicates a convex portion corresponding to a portion having an irregular interval, which has been formed in the process of anodizing and etching for producing a mold for forming a moth-eye structure. In FIG. 1D, the bottom of the gap between adjacent convex portions 4 has an inclined shape, but it may have a horizontal shape without being inclined.

The pitch P between the adjacent convex portions 4 is not particularly limited as long as it is equal to or less than the wavelength of visible light (780 nm). However, from the viewpoint of sufficiently preventing optical phenomena such as moire and rainbow unevenness, it is 100 nm or more and 400 nm or less. It is preferable that it is 100 nm or more and 200 nm or less. In the present specification, the pitch between adjacent convex portions of the optical film is a branch in a 1 μm square region of a planar photograph taken with a scanning electron microscope (product name: S-4700) manufactured by Hitachi High-Technologies Corporation. The average value of the distance between all adjacent convex parts excluding the protrusions. In addition, the pitch between adjacent convex portions is osmium oxide VIII (thickness made by Wako Pure Chemical Industries, Ltd.) on the concavo-convex structure of the polymer layer using an osmium coater (product name: Neoc-ST) made by Meiwa Forsys. : 5 nm) applied.

Although the height of the convex part 4 is not specifically limited, From the viewpoint of making it compatible with the preferable aspect ratio of the convex part 4 mentioned later, it is preferable that it is 50 nm or more and 600 nm or less, and it is more preferable that it is 100 nm or more and 300 nm or less. In the present specification, the height of the convex portion is 10 pieces arranged continuously except for branch protrusions in a cross-sectional photograph taken with a scanning electron microscope (product name: S-4700) manufactured by Hitachi High-Technologies Corporation. The average value of the height of a convex part is shown. However, when selecting ten convex portions, the convex portion having a defect or a deformed portion (such as a portion deformed when preparing a sample) is excluded. As the sample, one sampled in an area where there is no specific defect of the optical film is used. For example, when the optical film is a roll produced continuously, the one sampled near the center is used. . In addition, the height of a convex part is osmium oxide VIII (thickness: 5 nm) made from a Wako Pure Chemical Industries Ltd. on the uneven structure of a polymer layer using the osmium coater (product name: Neoc-ST) made from Meiwaforsys. ) Is applied.

Although the aspect ratio of the convex part 4 is not specifically limited, It is preferable that it is 0.8 or more and 1.5 or less. When the aspect ratio of the convex portion 4 is 1.5 or less, the workability of the moth-eye structure is sufficiently increased, sticking occurs, or the transfer condition when forming the moth-eye structure is deteriorated (the mold is clogged). Or concerns about it) When the aspect ratio of the convex portion 4 is 0.8 or more, optical phenomena such as moire and rainbow unevenness can be sufficiently prevented, and good reflection characteristics can be realized. In this specification, the aspect ratio of a convex part refers to the ratio (height / pitch) of the pitch between adjacent convex parts and the height of a convex part measured by the method as mentioned above.

The arrangement of the protrusions 4 is not particularly limited, and may be arranged randomly or regularly. From the viewpoint of sufficiently preventing the occurrence of moiré, it is preferably arranged randomly.

As mentioned above, according to the manufacturing method of the optical film of Embodiment 1, the optical film 1 excellent in antifouling property and abrasion resistance can be manufactured.

Next, the metal mold | die of Embodiment 1 is demonstrated below with reference to FIG. FIG. 2 is a schematic cross-sectional view illustrating the mold according to the first embodiment.

The mold 6 has a plurality of recesses provided on the surface at a pitch Q (distance between the bottom points of adjacent recesses) Q that is equal to or less than the wavelength of visible light. Therefore, according to the mold 6, a moth-eye structure can be formed on the surface of the object (for example, a resin layer). The mold 6 contains aluminum atoms and oxygen atoms as constituent atoms.

A mold release agent 7 is disposed on the surface of the mold 6. The release agent 7 contains carbon atoms, oxygen atoms, and fluorine atoms as constituent atoms. Thereby, the mold 6 having releasability and low surface energy is obtained.

Hexadecane is dropped on the surface of the mold 6 on which the mold release agent 7 is disposed, and the contact angle immediately after the hexadecane dropping measured by the θ / 2 method is θ _A (unit: °), contact after 4 minutes of hexadecane dropping. If the angle is defined as θ _B (unit: °), θ _A and θ _B are 85 ° or more, and the difference between θ _A and θ _B is 3.5 ° or less.

Carbon on the surface of the mold 6 on which the release agent 7 is disposed, measured by X-ray photoelectron spectroscopy under conditions of an X-ray beam diameter of 100 μm, an analysis area of 1000 μm × 500 μm, and a photoelectron extraction angle of 45 ° The ratio of the number of fluorine atoms to the total number of atoms, aluminum atoms, oxygen atoms, and fluorine atoms is 30 atom% or more.

If the contact angle and fluorine content of hexadecane on the surface of the mold 6 on which the release agent 7 is disposed are within the above ranges, the release effect by the release agent 7 can be sufficiently obtained. Therefore, the metal mold | die of Embodiment 1 is preferably used when manufacturing the optical film excellent in antifouling property and abrasion resistance.

As an example of the metal mold | die of Embodiment 1, the metal mold | die used for the manufacturing method of the optical film of Embodiment 1 mentioned above is mentioned.

[Embodiment 2]
The manufacturing method of the optical film of Embodiment 2 is demonstrated below with reference to FIG. FIG. 3 is a schematic cross-sectional view for explaining a manufacturing process of the optical film of Embodiment 2 (steps a to e). Since the manufacturing method of the optical film of Embodiment 2 is the same as the manufacturing method of the optical film of Embodiment 1 except that the lower layer resin and the upper layer resin are sequentially applied onto the base film, the overlapping points will be described. Omitted as appropriate. In addition, since the metal mold | die of Embodiment 2 is the same as the metal mold | die of Embodiment 1, description is abbreviate | omitted.

(A) Application of lower layer resin First, the lower layer resin 5a is applied on the base film 2 as shown in FIG.

(B) Application of upper layer resin As shown in FIG. 3B, an upper layer resin 5b is applied on the applied lower layer resin 5a. As a result, the upper layer resin 5b is formed on the side opposite to the base film 2 of the lower layer resin 5a.

(C) Formation of concavo-convex structure As shown in FIG. 3 (c), the lower layer resin 5a and the upper layer are applied in a state where the applied lower layer resin 5a and the upper layer resin 5b are sequentially laminated from the base film 2 side. A mold 6 is pressed against the resin 5b from the upper resin 5b side to form a resin layer 8 having an uneven structure on the surface. A mold release agent 7 is applied to the surface of the mold 6 in advance.

(D) The resin layer 8 on which the concavo-convex structure of the resin layer is formed is cured. As a result, a polymer layer 3 as shown in FIG. 3 (d) is formed.

(E) Mold Release The mold 6 having the release agent 7 applied on the surface thereof is released from the polymer layer 3. As a result, the optical film 1 as shown in FIG.

[Embodiment 3]
The manufacturing method of the optical film of Embodiment 3 is demonstrated below with reference to FIG. FIG. 4 is a schematic cross-sectional view for explaining the manufacturing process of the optical film of Embodiment 3 (steps a to d). Since the manufacturing method of the optical film of Embodiment 3 is the same as the manufacturing method of the optical film of Embodiment 1 except that the lower layer resin and the upper layer resin are simultaneously coated on the base film, the overlapping points will be described. Omitted as appropriate. In addition, since the metal mold | die of Embodiment 3 is the same as the metal mold | die of Embodiment 1, description is abbreviate | omitted.

(A) Application of lower layer resin and upper layer resin First, as shown in FIG. 4A, the lower layer resin 5 a and the upper layer resin 5 b are simultaneously applied onto the base film 2. As a result, the upper layer resin 5b is formed on the side opposite to the base film 2 of the lower layer resin 5a. As a method of applying the lower layer resin 5a and the upper layer resin 5b at the same time, for example, a method of applying by a coextrusion method can be mentioned.

(B) Formation of concavo-convex structure As shown in FIG. 4 (b), the lower layer resin 5a and the upper layer are applied in the state where the applied lower layer resin 5a and the upper layer resin 5b are sequentially laminated from the base film 2 side. A mold 6 is pressed against the resin 5b from the upper resin 5b side to form a resin layer 8 having an uneven structure on the surface. A mold release agent 7 is applied to the surface of the mold 6 in advance.

(C) The resin layer 8 on which the cured uneven structure of the resin layer is formed is cured. As a result, a polymer layer 3 as shown in FIG. 4C is formed.

(D) Mold Release The mold 6 having the release agent 7 applied on its surface is released from the polymer layer 3. As a result, the optical film 1 as shown in FIG.

According to the manufacturing method of the optical film of Embodiment 3, since the lower layer resin 5a and the upper layer resin 5b are applied simultaneously, the number of steps can be reduced as compared with the manufacturing method of the optical film of Embodiment 2.

[Embodiment 4]
The manufacturing method of the optical film of Embodiment 4 is demonstrated below with reference to FIG. FIG. 5 is a schematic cross-sectional view for explaining the manufacturing process of the optical film of Embodiment 4 (steps a to e). Since the manufacturing method of the optical film of Embodiment 4 is the same as the manufacturing method of the optical film of Embodiment 1 except that the upper layer resin and the lower layer resin are sequentially applied onto the mold, the explanation of overlapping points is appropriately given. Omitted. In addition, since the metal mold | die of Embodiment 4 is the same as the metal mold | die of Embodiment 1, description is abbreviate | omitted.

(A) Application of upper layer resin First, as shown in FIG. 5A, the upper layer resin 5 b is applied on the mold 6. A mold release agent 7 is applied to the surface of the mold 6 in advance.

(B) Application of lower layer resin As shown in FIG. 5B, a lower layer resin 5a is applied on the applied upper layer resin 5b. As a result, the lower layer resin 5a is formed on the side opposite to the mold 6 of the upper layer resin 5b.

(C) Formation of concavo-convex structure As shown in FIG. 5 (c), the applied upper layer resin 5b and lower layer resin 5a are sequentially laminated from the mold 6 side, and the lower layer resin 5a and the upper layer resin. The base film 2 is pressed against the lower resin 5a side, that is, the mold 6 is pressed against the lower resin 5a and the upper resin 5b from the upper resin 5b side, thereby forming the resin layer 8 having a concavo-convex structure on the surface.

(D) The resin layer 8 on which the concavo-convex structure of the resin layer is formed is cured. As a result, a polymer layer 3 as shown in FIG. 5 (d) is formed.

(E) Mold Release The mold 6 having the release agent 7 applied on the surface thereof is released from the polymer layer 3. As a result, the optical film 1 as shown in FIG.

Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples.

(Materials and components)
In Examples and Comparative Examples, materials and members used for producing optical films are as follows.

(Lower layer resin LR-1)
A mixture of the following materials (acrylic resin) was used. In addition, the numerical value attached | subjected to each material shows the density | concentration of each component in lower layer resin.
Urethane acrylate (“UA-7100” manufactured by Shin-Nakamura Chemical Co., Ltd.): 31.8% by weight
Pentaerythritol triacrylate (“A-TMM-3LM-N” manufactured by Shin-Nakamura Chemical Co., Ltd.): 28.2% by weight
Ethoxylated pentaerythritol tetraacrylate (“ATM-35E” manufactured by Shin-Nakamura Chemical Co., Ltd.): 40% by weight

(Upper layer resin UR-1)
A mixture of the following materials (fluorine resin) was used. In addition, the numerical value attached | subjected to each material shows the density | concentration of each component in upper layer resin. The active ingredient concentration (solid content concentration) of the upper layer resin UR-1 was 20% by weight.
4-acryloylmorpholine: 75% by weight or more and 85% by weight or less Perfluoropolyether: 15% by weight or more and 25% by weight or less

(Upper layer resin UR-2)
The same thing as upper layer resin UR-1 was used except having changed the active ingredient density | concentration (solid content density | concentration) into 10 weight%.

(Upper layer resin UR-3)
The same thing as upper resin UR-1 was used except having changed the active ingredient density | concentration (solid content density | concentration) into 5 weight%.

(Mold M-1)
First, aluminum was deposited on a 10 cm square glass substrate by a sputtering method. The thickness of the formed aluminum layer was 1.0 μm. Next, by repeating the anodic oxidation and etching alternately on the formed aluminum layer, a large number of minute holes (the distance between the bottom points of adjacent holes is less than the wavelength of visible light) are provided. An anodized layer was formed. Specifically, anodization, etching, anodization, etching, anodization, etching, anodization, etching, and anodization are sequentially performed (anodization: 5 times, etching: 4 times), thereby forming the inside of aluminum. A large number of minute holes (concave portions) having a shape (tapered shape) that narrows toward the surface are formed, and as a result, a mold M-1 having an uneven structure is obtained. The size of the mold M-1 was 5 cm × 10 cm. Anodization was performed using oxalic acid (concentration: 0.03% by weight) under conditions of a liquid temperature of 5 ° C. and an applied voltage of 80V. The time for one anodic oxidation was 25 seconds. Etching was performed using phosphoric acid (concentration: 1 mol / l) at a liquid temperature of 30 ° C. The time for performing one etching was set to 25 minutes. The surface specification of the mold M-1 was as follows.
・ Pitch Q between adjacent recesses: 200 nm
-Depth of recess: 400nm

Then, the mold release process was performed by apply | coating a mold release agent to the surface of metal mold | die M-1. As a release agent, a solution in which “OPTOOL DSX” manufactured by Daikin Industries, Ltd. was diluted with perfluorohexane to a solid content concentration of 0.1% by weight was used. The release agent thickness Dc was 2 to 3 nm.

(Mold M-2 to M-6)
Resin is continuously transferred using a mold similar to the mold M-1, and the mold M-2, the mold M-3, the mold M-4, and the mold M are arranged in the order of short usage period. -5 and mold M-6 (mold with the longest use period) were prepared.

[Evaluation of molds]
For the molds M-1 to M-6, (i) contact angles (water and hexadecane) and (ii) fluorine content on the surface to which the release agent was applied were measured. The measurement results are shown in Tables 1 and 2.

(I) Water (pure water) and hexadecane are dropped on the surface of each mold coated with the contact angle release agent, immediately after dropping, 1 minute, 2 minutes, 3 minutes later, and 4 The contact angle after minutes was measured. Tables 1 and 2 also show the difference between the contact angle immediately after dropping and the contact angle 4 minutes after dropping. Note that “impregnation impossible” refers to a state where the contact angle is too large to allow droplet deposition.

(Ii) Measurement by X-ray photoelectron spectroscopy was performed on the surface of each mold coated with a fluorine content release agent. Specifically, first, a survey spectrum of the surface of each mold coated with a release agent was measured. The measurement conditions for the survey spectrum were as follows.
・ X-ray beam diameter: 100 μm (12.5 W, 15 kV)
・ Analysis area: 1000 μm × 500 μm
-Photoelectron extraction angle: 45 °
・ Pass energy: 224eV

As a result of measuring the survey spectrum, C1s peak, Al2p peak, O1s peak, and F1s peak were detected in each mold. The release agent applied to the surface of each mold contained carbon atoms, oxygen atoms, and fluorine atoms as constituent atoms, and the F1s peak was derived from the release agent. Each die contained aluminum atoms and oxygen atoms as constituent atoms, and the Al2p peak was derived from the die.

Next, from the obtained survey spectrum, fluorine atoms relative to the total number of carbon atoms, aluminum atoms, oxygen atoms, and fluorine atoms on the surface of each mold coated with a release agent The ratio of the number (fluorine content) was calculated. The fluorine content on the surface of the mold coated with the mold release agent, obtained by measurement by X-ray photoelectron spectroscopy, is the fluorine content in the region within 6 nm in the depth direction from the outermost surface of the mold release agent. Point to.

As shown in Table 1, in each of the molds M-1 to M-3, the contact angle immediately after dropping the hexadecane on the surface and the contact angle after 4 minutes of dropping the hexadecane are 85 ° or more, and both The difference was 3.5 ° or less. Further, all of the molds M-1 to M-3 had a fluorine content of 30 atom% or more on the surface.

On the other hand, as shown in Table 2, in the mold M-4, the contact angle immediately after dropping of hexadecane on the surface and the contact angle after 4 minutes of dropping of hexadecane were less than 85 °. Furthermore, the mold M-4 had a fluorine content of less than 30 atom% on the surface.

As shown in Table 2, the mold M-5 had a contact angle of 85 ° or more immediately after the hexadecane dropping on the surface, but the contact angle after 4 minutes of hexadecane dropping was less than 85 °, and the difference between the two was It was larger than 3.5 °. Furthermore, the mold M-5 had a fluorine content on the surface of less than 30 atom%.

As shown in Table 2, in the mold M-6, the contact angle immediately after dropping hexadecane on the surface and the contact angle after 4 minutes from dropping hexadecane were less than 85 °, and the difference between the two was 3.5 °. It was bigger than. Further, the mold M-6 had a fluorine content of less than 30 atom% on the surface.

Example 1
The optical film of Example 1 was produced by the optical film manufacturing method of Embodiment 4.

(A) Application of upper layer resin First, the upper layer resin 5b was applied onto the mold 6 (on the surface of the mold 6 coated with the release agent 7) by dropping it with a dropper.

The upper layer resin UR-1 described above was used as the upper layer resin 5b. The thickness Db of the upper layer resin 5b was 1 μm. The mold M-2 described above was used as the mold 6 with the release agent 7 applied on the surface.

(B) Coating of the lower layer resin The lower layer resin 5a was coated on the upper layer resin 5b (on the surface opposite to the mold 6 of the upper layer resin 5b) by dropping with a dropper.

As the lower layer resin 5a, the lower layer resin LR-1 described above was used. The thickness Da of the lower layer resin 5a was 8 μm.

(C) Convex / concave structure formation The upper layer resin 5b and the lower layer resin 5a are laminated in order from the mold 6 side, and on the lower layer resin 5a (the surface opposite to the upper layer resin 5b of the lower layer resin 5a) The upper film was covered with the base film 2, and the base film 2 was pressed against the lower resin 5a side with a roller. That is, the mold 6 coated with the upper layer resin 5b and the lower layer resin 5a was pressed against the base film 2. As a result, a resin layer 8 having an uneven structure on the surface opposite to the base film 2 was formed.

As the base film 2, a polyethylene terephthalate film with an easy-adhesion layer (product name: Cosmo Shine (registered trademark) A4300) manufactured by Toyobo Co., Ltd. was used. The thickness of the base film 2 was 60 μm.

(D) The resin layer 8 on which the cured uneven structure of the resin layer was formed was cured (polymerized) by irradiation with ultraviolet rays (irradiation amount: 1.2 J / cm ² ) from the base film 2 side. As a result, the polymer layer 3 (cured product of the resin layer 8) was formed.

(E) Mold Release The mold 6 having the release agent 7 applied on its surface was released from the polymer layer 3. As a result, the optical film 1 was completed. The surface specification of the optical film 1 was as follows.
・ Shape of convex part 4: bell shape ・ Pitch P between adjacent convex parts 4: 200 nm
-Height of convex part 4: 250 nm
-Aspect ratio of convex part 4: 1.25

(Examples 2 to 5 and Comparative Examples 1 to 5)
Optical films of respective examples were produced in the same manner as in Example 1 except that the materials and members were changed as shown in Tables 3 to 8. In addition, the description of each material and each member in Tables 3-8 is as follows.
<Lower layer resin>
"LR-1": Lower layer resin LR-1
<Upper layer resin>
"UR-1" to "UR-3": Upper resin UR-1 to UR-3
<Mold>
・ "M-1" to "M-6": Molds M-1 to M-6

[Evaluation of optical film]
The optical films of Examples 1 to 5 and Comparative Examples 1 to 5 were evaluated for antifouling properties and abrasion resistance. The results are shown in Tables 3-8.

(Anti-fouling property)
As antifouling property, (i) contact angles (water and hexadecane) and (ii) fluorine content on the surface of the optical film of each example were evaluated.

(I) Contact angle Water (pure water) and hexadecane are dropped on the surface of the optical film of each example (the surface opposite to the base film of the polymer layer), and immediately after dropping, 1 minute later, 2 The contact angles after 3 minutes, 3 minutes and 4 minutes were measured.

(Ii) Fluorine Content A measurement by X-ray photoelectron spectroscopy was performed on the surface of the optical film of each example (the surface on the side opposite to the base film of the polymer layer). Specifically, first, a survey spectrum of the surface of the optical film of each example was measured. The measurement conditions for the survey spectrum were as follows.
・ X-ray beam diameter: 100 μm (12.5 W, 15 kV)
・ Analysis area: 1000 μm × 500 μm
-Photoelectron extraction angle: 45 °
・ Pass energy: 224eV

As a result of measuring the survey spectrum, C1s peak, N1s peak, O1s peak, and F1s peak were detected in the optical film of each example. That is, it was found that the polymer layer of the optical film in each example contained carbon atoms, nitrogen atoms, oxygen atoms, and fluorine atoms as constituent atoms.

Next, from the obtained survey spectrum, the ratio of the number of fluorine atoms to the total number of carbon atoms, nitrogen atoms, oxygen atoms, and fluorine atoms on the surface of the polymer layer (fluorine content) Rate) was calculated. Note that the fluorine content on the surface of the polymer layer obtained by measurement by X-ray photoelectron spectroscopy refers to the fluorine content in a region within 6 nm in the depth direction from the outermost surface of the polymer layer.

(Abrasion resistance)
As the abrasion resistance, (i) friction resistance and (ii) steel wool resistance on the surface of the optical film of each example were evaluated.

(I) Friction resistance The surface of the optical film of each example (the surface opposite to the base film of the polymer layer) was applied to steel wool (product name: # 0000) manufactured by Nippon Steel Wool Co., Ltd. with a load of 400 g. The state was rubbed once, and the dynamic friction resistance value at that time was measured. When rubbing with steel wool, a surface property measuring machine (product name: 14FW) manufactured by Shinto Kagaku Co., Ltd. was used as a testing machine, and the stroke width was 20 mm and the speed was 0.5 mm / s.

(Ii) Steel wool resistance The surface of the optical film of each example (surface opposite to the base film of the polymer layer) is subjected to a predetermined load on steel wool (product name: # 0000) manufactured by Nippon Steel Wool Co., Ltd. The load at the time of rubbing and scratching in the applied state was used as an evaluation index. When rubbing with steel wool, a surface property measuring machine (product name: 14FW) manufactured by Shinto Kagaku Co., Ltd. was used as a tester, the stroke width was 10 mm, the speed was 100 mm / s, and the number of times of rubbing was 10 reciprocations. Also, the presence or absence of scratches was confirmed by visual observation under an environment with an illuminance of 100 lx (fluorescent lamp). Judgment criteria were as follows.
○: Steel wool resistance was 80 g or more.
Δ: Steel wool resistance was 30 g or more and less than 80 g.
X: Steel wool resistance was less than 30 g.

As shown in Tables 3-8, Examples 1-5 had higher fluorine content on the surface of the optical film (the surface of the polymer layer) than Comparative Examples 1-5. In Examples 1 to 5, the contact angles of water and hexadecane (particularly, the contact angle immediately after dropping) with respect to the surface of the optical film were larger than those of Comparative Examples 1 to 5. For example, when Example 1 and Comparative Example 1 in which the types of the lower layer resin and the upper layer resin are the same are compared, the contact angle of water with respect to the surface of the optical film (immediately after dropping) is larger than 140 ° in Example 1. Although it could not be dropped, in Comparative Example 1, it was 101.3 °. Therefore, Example 1 was superior in water repellency to Comparative Example 1. Further, the contact angle of hexadecane with respect to the surface of the optical film (immediately after dropping) was 89.5 ° in Example 1, whereas it was smaller than 20 ° in Comparative Example 1. Therefore, Example 1 was more excellent in oil repellency than Comparative Example 1. From the above, Examples 1 to 5 were superior in antifouling properties to Comparative Examples 1 to 5.

As shown in Tables 3-8, Examples 1-5 had smaller frictional resistance and better steel wool resistance than Comparative Examples 1-5. Therefore, Examples 1-5 were more excellent in abrasion resistance than Comparative Examples 1-5.

From the above, Examples 1 to 5 were more excellent in antifouling properties and abrasion resistance than Comparative Examples 1 to 5. That is, the contact angle immediately after dropping of hexadecane on the surface and the contact angle after 4 minutes of dropping of hexadecane are 85 ° or more, the difference between them is 3.5 ° or less, and the fluorine content on the surface is 30 atom%. It was found that if the above molds (molds M-1 to M-3) were used, an optical film excellent in antifouling property and abrasion resistance was obtained.

The result of further analyzing the optical films of Examples 1 to 3 and Comparative Examples 1 and 2 will be described below.

First, from the survey spectrum obtained by the method described above, each number other than fluorine atoms with respect to the total number of carbon atoms, nitrogen atoms, oxygen atoms, and fluorine atoms on the surface of the polymer layer. The ratio of the number of atoms was calculated. Table 9 shows the calculation results. Table 9 also shows the above-described fluorine content (ratio of the number of fluorine atoms).

As shown in Table 9, in Examples 1 to 3, it was found that the fluorine atoms were oriented at a higher concentration on the surface of the polymer layer than in Comparative Examples 1 and 2.

Next, the narrow spectrum of the surface of the optical film of each example was measured by X-ray photoelectron spectroscopy. 6 is a graph showing the narrow spectra of the optical films of Examples 1 to 3 and Comparative Examples 1 and 2, wherein (a) shows the C1s peak, (b) shows the N1s peak, c) shows the O1s peak, and (d) shows the F1s peak. “C / s” on the vertical axis in FIG. 6 is an abbreviation for “counts / second”. The same applies to other drawings. The measurement conditions for the narrow spectrum were as follows.
・ X-ray beam diameter: 100 μm (12.5 W, 15 kV)
・ Analysis area: 1000 μm × 500 μm
-Photoelectron extraction angle: 45 °
・ Pass energy: 112eV

Next, each of the C1s peak and O1s peak of the obtained narrow spectrum was separated into a plurality of peaks, and a binding species corresponding to each peak was identified from each peak position and shape.

FIG. 7 is a graph showing the analysis result of the C1s peak of Example 1 in FIG. FIG. 8 is a graph showing the analysis result of the C1s peak of Example 2 in FIG. FIG. 9 is a graph showing the analysis result of the C1s peak of Example 3 in FIG. FIG. 10 is a graph showing the analysis result of the C1s peak of Comparative Example 1 in FIG. FIG. 11 is a graph showing the analysis result of the C1s peak of Comparative Example 2 in FIG. 7 to 11, the peak Cs corresponds to the C1s peak of each example in FIG. On the other hand, the peaks C1 to C7 are spectra obtained by curve fitting with peaks derived from each bond type with respect to the peak Cs (C1s peak). Note that the obtained spectrum was subjected to charge correction so that the position of the peak C1 was 284.6 eV.

Table 10 shows the positions of the peaks C1 to C7 and the identified binding species. In identifying each binding species, the information described in Non-Patent Document 1 and Table 1 of Non-Patent Document 2 were used.

As shown in Table 10, the peak C7 is identified as “CF ₃ bond and OCF ₂ bond”. However, as shown in Table 1 of Non-Patent Document 2, the peak derived from the CF ₃ bond and the OCF ₂ bond are shown. Since it is located at almost the same position as the peak derived from it, it was difficult to separate the two peaks.

FIG. 12 is a graph showing the analysis result of the O1s peak of Example 1 in FIG. FIG. 13 is a graph showing the analysis result of the O1s peak of Example 2 in FIG. FIG. 14 is a graph showing the analysis result of the O1s peak of Example 3 in FIG. FIG. 15 is a graph showing the analysis result of the O1s peak of Comparative Example 1 in FIG. FIG. 16 is a graph showing the analysis result of the O1s peak of Comparative Example 2 in FIG. 12 to 16, the peak Os corresponds to the O1s peak in each example in FIG. On the other hand, the peaks O1 to O3 are spectra obtained by curve fitting with peaks derived from each bond type with respect to the peak Os (O1s peak).

Table 11 shows the positions of the peaks O1 to O3 and the identified binding species. In identifying each binding species, the information described in Non-Patent Document 3 and FIG. 2 of Non-Patent Document 4 were used.

From the above, in Examples 1 to 3 and Comparative Examples 1 and 2, each of the C1s peak and the O1s peak of the narrow spectrum on the surface of the optical film could be separated into peaks derived from each bond type.

Next, the composition ratio of each bond type on the surface of the polymer layer was calculated from the obtained narrow spectrum. The calculation results are shown in Tables 12 and 13.

As shown in Table 12 and Table 13, in Examples 1 to 3, it was found that the fluorine atoms were oriented at a higher concentration on the surface of the polymer layer than in Comparative Examples 1 and 2.

[Appendix]
One aspect of the present invention is a method for producing an optical film having a concavo-convex structure provided on the surface with a plurality of convex portions provided at a pitch equal to or less than the wavelength of visible light, the step of applying a lower layer resin and an upper layer resin (1); In the state where the applied lower layer resin and the upper layer resin are laminated, a mold is pressed against the lower layer resin and the upper layer resin from the upper layer resin side to form a resin layer having the concavo-convex structure on the surface ( 2) and the step (3) of curing the resin layer, the upper layer resin contains a fluorine-containing monomer, and a mold release agent is applied to the surface of the mold, and the mold release agent Includes carbon atoms, oxygen atoms, and fluorine atoms as constituent atoms, and the mold includes aluminum atoms and oxygen atoms as constituent atoms, on the surface of the mold on which the release agent is applied. Hexadecane is dropped measured by theta / 2 method, the contact angle immediately after hexadecane dropwise theta _{A (Unit:} °), the contact angle after hexadecane dropwise 4 minutes theta _{B (unit:} °) Defining a, theta _A and theta _B is 85 ° or more, and the difference between θ _A and θ _B is 3.5 ° or less, an X-ray beam diameter of 100 μm, an analysis area of 1000 μm × 500 μm, and a photoelectron extraction angle of 45 °. Fluorine relative to the total number of carbon atoms, aluminum atoms, oxygen atoms, and fluorine atoms on the surface of the mold coated with the release agent, as measured by X-ray photoelectron spectroscopy The ratio of the number of atoms may be a method for producing an optical film that is 30 atom% or more.

“Applying the lower layer resin and the upper layer resin” in the step (1) is not limited to the case where the lower layer resin and the upper layer resin are applied on the same member, but the lower layer resin and the upper layer resin are different. This includes the case where it is applied onto a member. As a case where the lower layer resin and the upper layer resin are applied on different members, for example, the lower layer resin may be applied onto a base film and the upper layer resin may be applied onto the mold.

In the step (2), “pressing a mold from the upper layer resin side to the lower layer resin and the upper layer resin in a state where the applied lower layer resin and the upper layer resin are laminated” means the lower layer This includes not only the case where the mold is pressed after the resin and the upper layer resin are laminated, but also the case where the mold is pressed while the lower layer resin and the upper layer resin are laminated. In other words, in the step (2), the lower layer resin and the upper layer resin are laminated (hereinafter also referred to as a lamination step), and the mold is attached to the lower layer resin and the upper layer resin from the upper layer resin side. It includes a method of performing pressing (hereinafter also referred to as pressing step) at the same timing or at different timings.

As a method of performing the lamination step and the pressing step at the same timing, the following method (i) is preferable.

(I) The lower layer resin is coated on a base film, the upper layer resin is coated on the mold, and then the mold coated with the upper layer resin is moved from the upper layer resin side to the base material. The upper layer resin is laminated on the lower layer resin (the laminating step) while pressing against the lower layer resin applied on the film (the pressing step).
That is, the step (1) is performed by applying the lower layer resin on a base film and applying the upper layer resin on the mold, and the step (2) is performed by applying the upper layer resin. Alternatively, the mold may be pressed from the upper layer resin side against the lower layer resin coated on the base film. In this case, the concavo-convex structure can be formed while laminating the upper layer resin on the lower layer resin. Furthermore, the number of steps can be reduced as compared with the case where the lower layer resin and the upper layer resin are sequentially applied onto the base film (method (ii) described later). Further, according to this method, the antifouling property can be preferably increased, and in particular, the loss of the constituent material of the upper layer resin can be minimized.

As a method of performing the lamination step and the pressing step at different timings, the following methods (ii) to (v) are preferable.

(Ii) The lower layer resin and the upper layer resin are sequentially applied onto the base film (the lamination step), and then the mold is pressed against the lower layer resin and the upper layer resin from the upper layer resin side (the pressing step). ).
That is, the said process (1) may be performed by apply | coating the said lower layer resin and the said upper layer resin in order on a base film. In this case, the lower layer resin and the upper layer resin can be efficiently applied by providing an apparatus of a general application method (for example, gravure method, slot die method, etc.).

(Iii) The lower layer resin and the upper layer resin are simultaneously coated on the base film (the upper layer resin is formed on the side opposite to the base film of the lower layer resin) (the layering step), and then The mold is pressed against the lower layer resin and the upper layer resin from the upper layer resin side (the pressing step).
That is, the said process (1) may be performed by apply | coating the said lower layer resin and the said upper layer resin simultaneously on a base film. In this case, the lower layer resin and the upper layer resin can be efficiently applied. Furthermore, since the coating apparatus can be simplified and the number of steps can be reduced as compared with the case where the lower layer resin and the upper layer resin are sequentially applied onto the base film (the method (ii) described above), the productivity is increased. .

(Iv) The upper layer resin and the lower layer resin are sequentially applied onto the mold (the laminating step), and then the mold on which the upper layer resin and the lower layer resin are applied is pressed against the base film ( Pressing step above).
That is, the step (1) may be performed by sequentially applying the upper layer resin and the lower layer resin onto the mold. In this case, for example, if a flexible mold is used as the mold, the uneven structure can be easily formed regardless of the shape of the base film.

(V) The upper layer resin and the lower layer resin are simultaneously coated on the mold (the lower layer resin is formed on the opposite side of the mold of the upper layer resin) (the laminating step), and then The mold on which the upper layer resin and the lower layer resin are applied is pressed against the base film (the pressing step).
That is, the step (1) may be performed by simultaneously applying the upper layer resin and the lower layer resin on the mold. In this case, for example, if a flexible mold is used as the mold, the uneven structure can be easily formed regardless of the shape of the base film.

1: Optical film 2: Base film 3: Polymer layer 4: Convex part 5a: Lower layer resin 5b: Upper layer resin 6: Mold 7: Release agent 8: Resin layer P, Q: Pitch D: Polymer layer Thickness Da: Lower layer resin thickness Db: Upper layer resin thickness Dc: Release agent thickness C1, C2, C3, C4, C5, C6, C7, Cs, O1, O2, O3, Os: Peak

Claims (3)

A method for producing an optical film having a concavo-convex structure provided on the surface with a plurality of convex portions provided at a pitch equal to or less than the wavelength of visible light,
Applying the lower layer resin on the base film and applying the upper layer resin on the mold (1);
(2) forming the resin layer having the concavo-convex structure on the surface by pressing the mold coated with the upper layer resin from the upper layer resin side against the lower layer resin coated on the base film; ,
Curing the resin layer (3),
The upper layer resin contains a fluorine-containing monomer,
A mold release agent is applied to the surface of the mold,
The release agent contains carbon atoms, oxygen atoms, and fluorine atoms as constituent atoms,
The mold includes aluminum atoms and oxygen atoms as constituent atoms,
Hexadecane is dropped on the surface of the mold on which the release agent is applied, and the contact angle immediately after the hexadecane drop measured by the θ / 2 method is θ _A (unit: °), contact after 4 minutes of hexadecane drop. If the angle is defined as θ _B (unit: °), θ _A and θ _B are 85 ° or more, and the difference between θ _A and θ _B is 3.5 ° or less,
Carbon on the surface of the mold coated with the release agent, measured by X-ray photoelectron spectroscopy under conditions of an X-ray beam diameter of 100 μm, an analysis area of 1000 μm × 500 μm, and a photoelectron extraction angle of 45 ° The ratio of the number of fluorine atoms to the total number of atoms, aluminum atoms, oxygen atoms, and fluorine atoms is 30 atom% or more. A method for producing an optical film having a concavo-convex structure provided on the surface with a plurality of convex portions provided at a pitch equal to or less than the wavelength of visible light
A step (1) of simultaneously applying a lower layer resin and an upper layer resin on a base film;
A step (2) of pressing a mold from the upper layer resin side to the lower layer resin and the upper layer resin applied on the base film to form a resin layer having the concavo-convex structure on the surface;
Curing the resin layer (3),
The upper layer resin contains a fluorine-containing monomer,
A mold release agent is applied to the surface of the mold,
The release agent contains carbon atoms, oxygen atoms, and fluorine atoms as constituent atoms,
The mold includes aluminum atoms and oxygen atoms as constituent atoms,
Hexadecane is dropped on the surface of the mold coated with the release agent, and the contact angle immediately after dropping of hexadecane is measured by the θ / 2 method. _A (Unit: °), the contact angle after 4 minutes of hexadecane dripping is θ _B If defined as (unit: °), θ _A And θ _B Is 85 ° or more and θ _A And θ _B And the difference is 3.5 ° or less,
Carbon on the surface of the mold coated with the release agent, measured by X-ray photoelectron spectroscopy under conditions of an X-ray beam diameter of 100 μm, an analysis area of 1000 μm × 500 μm, and a photoelectron extraction angle of 45 ° The method for producing an optical film, wherein a ratio of the number of fluorine atoms to the total number of atoms, aluminum atoms, oxygen atoms, and fluorine atoms is 30 atom% or more. A method for producing an optical film having a concavo-convex structure provided on the surface with a plurality of convex portions provided at a pitch equal to or less than the wavelength of visible light
A step (1) of sequentially applying an upper layer resin and a lower layer resin on the mold;
A step (2) of pressing the mold coated with the upper layer resin and the lower layer resin on the base film from the lower layer resin side to form a resin layer having the concavo-convex structure on the surface;
Curing the resin layer (3),
The upper layer resin contains a fluorine-containing monomer,
A mold release agent is applied to the surface of the mold,
The release agent contains carbon atoms, oxygen atoms, and fluorine atoms as constituent atoms,
The mold includes aluminum atoms and oxygen atoms as constituent atoms,
Hexadecane is dropped on the surface of the mold coated with the release agent, and the contact angle immediately after dropping of hexadecane is measured by the θ / 2 method. _A (Unit: °), the contact angle after 4 minutes of hexadecane dripping is θ _B If defined as (unit: °), θ _A And θ _B Is 85 ° or more and θ _A And θ _B And the difference is 3.5 ° or less,
Carbon on the surface of the mold coated with the release agent, measured by X-ray photoelectron spectroscopy under conditions of an X-ray beam diameter of 100 μm, an analysis area of 1000 μm × 500 μm, and a photoelectron extraction angle of 45 ° The method for producing an optical film, wherein a ratio of the number of fluorine atoms to the total number of atoms, aluminum atoms, oxygen atoms, and fluorine atoms is 30 atom% or more.

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